Photos of Electric discharge showing the lightning-like plasma filaments from a Tesla coil.­

A Tesla coil is a type of resonant transformer circuit invented by Serbian-American scientist Nikola Tesla around 1891.­ It is generally used to generate very high voltage, low current, high frequency alternating current electricity.­

It's very impressive to see the high-voltage lightnings arcs produced by large Tesla coils.­ Don't try this at home!